Generally, in designing a semiconductor integrated circuit, layout data is generated and a test is performed based on the layout data.
A scan test is well known as a method for testing the semiconductor integrated circuit. Nowadays a compression scan test that is of an application of the scan test is used. The compression scan test is performed using a scan test module incorporated in the semiconductor integrated circuit. The scan test module is a combination of a scan chain and a compression scan circuit. The compression scan circuit includes a decompressor and a compressor. One end of each of the decompressor and the compressor is connected to an external circuit (for example, semiconductor inspection apparatus) of the semiconductor integrated circuit. The other end of each of the decompressor and the compressor is connected to the scan chain. The scan chain is classified into groups (hereinafter referred to as “functional groups”) in each functional block. The compression scan circuit is disposed outside or inside the functional group.
However, in generating the layout data, when a cell position in the semiconductor integrated circuit is determined in a unit of functional group, positional relationship between cells, which relates to an operation signal of the semiconductor integrated circuit, is considered but positional relationship between cells, which relates to a scan signal for the scan test to be added, is not considered. In other words, when the cell position in the semiconductor integrated circuit is determined, an operation of the semiconductor integrated circuit is considered but the scan test is not considered in determination of the cell position.
Accordingly, a distance between the scan chain and the compression scan circuit is lengthened in the semiconductor integrated circuit, which is obtained based on the layout data. As a result, a wire length of a wire (hereinafter referred to as a “scan wire”) connecting the scan chain and the compression scan circuit increases, which obstructs integration of the semiconductor integrated circuit.